//
//  MainTabBar.swift
//  SinaWeibo
//
//  Created by yimin on 16/1/12.
//  Copyright © 2016年 yimin. All rights reserved.
//

import UIKit

class MainTabBar: UITabBar {

    override init(frame: CGRect) {
        super.init(frame: frame)
        addSubview(plusBtn)
    }
    
    //表示对象是通过 XIB创建
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        let w=self.bounds.width/5
        let h=self.bounds.height
        let rect=CGRect(x: 0, y: 0, width: w, height: h)
        var index:CGFloat=0
        //1.遍历子视图
        for subView in subviews {
            //2.获取所有的 UITabBarButton 类型的对象
            if subView.isKindOfClass(NSClassFromString("UITabBarButton")!) {
                subView.frame=CGRectOffset(rect, index * w, 0)
//                if index==1 {
//                    index++
//                }
                //三木运算
                index += (index == 1 ? 2 : 1)
            }
        }
        //修改加好按钮的位置
        plusBtn.frame=CGRectOffset(rect, 2*w, 0)
//        bringSubviewToFront(plusBtn)
    }
    // MARK: 懒加载获取加好按钮
    lazy var plusBtn:UIButton = {
        let btn=UIButton()
        //设置背景图片
        btn.setBackgroundImage(UIImage(named: "tabbar_compose_button"), forState: .Normal)
        btn.setBackgroundImage(UIImage(named: "tabbar_compose_button_highlighted"), forState: .Highlighted)
        
        //设置按钮的图片
        btn.setImage(UIImage(named: "tabbar_compose_icon_add"), forState: .Normal)
        btn.setImage(UIImage(named: "tabbar_compose_icon_add_highlighted"), forState: .Highlighted)
        
        btn.sizeToFit()
        
        return btn
    }()
}
